Subsurface tubular string perforator



Dec. 7, 1965 w. D. MYERS SUBSURFACE TUBULAH STRING PERFORATOR 3 Sheets-Sheet 1 Filed April 15, 1963 INVENTOR MLA/,QM D. MYEQS r rom/sys.

Dec. 7, 1965 Filed April 15, 1963 Lo. 3a.

W. D. MYERS SUBSURFACE TUBULAR STRING PERFORATOR 3 Sheets-Sheet 2 Ffa. 35. Pa. 3c. IZA/v0.

VW www@ `67 A Ef l2FK INVENTOR.

mam/Mw Dec. 7, 1965 w. D. MYERS 3,221,815

SUBSURFACE TUBULAR STRING PERFORATOR Filed April l5, 1963 3 Sheets-Sheet 5 EG. 4a

I NVENTOR.

WLM/QM 0. MYEQS Maui/MW faQ/VE Y6.

United States Patent C) M' 3,221,815 SUBSURFACE TUBULAR STRING PERFORATR William l). Myers, Houston, Tex., assignor to Baker Gil Tools, Inc., Los Angeles, Calif., a corporation of California lFiied Apr. 15, 1963, Ser. No. 273,089 12 Claims. (Cl. 166-55.3)

The present invention relates to subsurface well bore apparatus, and more particularly to apparatus for perforating tubular strings disposed in well bores, such as tubing, casing, or liner strings.

An object of the present invention is to provide mechanical perforating apparatus to be lowered in a tubular string on a wire line and capable of exerting a large cutting force for eifecting perforation of the tubular string.

Another object of the invention is to provide mechanical perforating apparatus to be lowered in a tubular string to perforate the same at a point which the apparatus can denitely locate, the apparatus being automatically releasable from the tubular string after the perforating operation to permit its withdrawal from the tubular string.

A further object of the invention is to provide mechanical perforating apparatus to be lowered in a tubular string and capable of becoming releasably locked to the tubular string, as at a tubular string coupling, the apparatus being capable of perforating the tubular string and automatically releasing itself from locked relation to the tubular string, enabling its withdrawal from the well bore.

An additional object of the invention is to provide mechanical perforating apparatus to be lowered in a tubular string in a well bore and embodying its own source of energy for effecting perforating of the tubular string.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings .accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best dened by the appended claims.

Referring to the drawings:

FIGURES la, lb, 1c and 1d together constitute a longitudinal section through a .perforating apparatus in condition for lowering through a tubular string to be perforated, FIGS. lb, lc and ld being lower continuations of FIGS. 1a, lb and lc, respectively;

FIG. 2 is an enlarged side elevation taken along the line 2-2 on FIG. 1c;

FIGS. 3a, 3b, 3c and 3d are views corresponding to FIGS. 1a to ld, disclosing the parts of the apparatus during a perforating operation, FIGS. 3b, 3c and 3d being lower continuations of FIGS. 3a, 3b and 3c, respectively;

FIGS. 4a and 4b together constitute a longitudinal section through the apparatus after the tubular string has been perforated and the apparatus released therefrom, FIG. 4b being a lower continuation of FIG. 4a;

FIG. 5 is a longitudinal section, with parts shown in elevation, of the perforating portion of the apparatus in its initial retracted position;

FIG. 6 is a view similar to FIG. 5 of the perforating apparatus upon perforating the tubular string;

FIG. 7 is a cross-section taken along the line 7 7 on FIG. 6.

The apparatus A disclosed in the drawings is adapted to be lowered through a tubular string B, such as a string of production tubing, to a desired location there- 3,221,815 Patented Dec. 7, 1965 within where the tubing is to be perforated, as by driving a hollow pin 10 through its wall, which is to remain therewithin, and thereby establish subsequent communication through the hollow pin between the interior and the exterior of the tubular string. The apparatus can be lowered and elevated in the tubular string on a wire line C extending to the surface of the well bore and can be positively located in the tubular string B, as through use of a coupling space 11 provided between adjacent upper and lower tubing sections 12, 13 connected to one another by an intervening coupling 14. The apparatus contains its own energy source, which provides the motivating power for effecting perforation of the tubing string, as well as yrelease of the perforating apparatus from the tubular string. Such motive power enables full operation and release of the apparatus without the necessity for imposing any substantial force on the wire line C.

The perforating apparatus A includes a power cylinder 15 comprising a cylinder sleeve 16, the yupper end of which is threadedly attached to an upper cylinder head 17, and the lower end of which is threadedly attached to the upper end of an elongate tubular housing 18. Secured within the lower portion of this housing is a mandrel 19 having an elongate slot 20 extending therethrough from the lower portion of the housing to the region of a transverse lopening 21 in the housing wall. The mandrel 19 projects downwardly through a lower inwardly directed flange 22 of the housing and into a lock or latch sleeve 23, longitudinal movement between the mandrel and housing being prevented by a retaining ring 24, such as a split snap ring, disposed within a peripheral groove 25 in the mandrel and engaging the lower end of the housing flange 22.

The lock or latch sleeve 23 constitutes part of a locating and holding device 26 for definitely positioning the perforating apparatus in the tubing string. This sleeve has a longitudinal slot 27 in which an upwardly holding latch member 28 is pivotally carried, as by mounting it on a pivot pin 29 secured to the sleeve 23 and extending across the slot. The upper end of the latch is constituted as an upwardly holding dog 30 urged outwardly of the sleeve by a helical compression spring 31, the inner end of which bears against the sleeve and the outer end of which bears against the dog. Such dog is adapted to be shifted outwardly into the coupling space 11 to engage the lower end 32 of the upper tubing section 12 and prevent upward movement of the sleeve 23 therewithin. The latch has a lower inwardly projecting retracting nose 33 initially received within an external longitudinal groove 34 in the mandrel, such retracting nose being engageable by an upper tapered end 35 of the groove to be shifted outwardly, so as to shift the latch dog 30 inwardly from the space 11 and substantially within the contines of the sleeve 23.

The latch sleeve 23 also carries a downwardly holding latch member 36 mounted in a longitudinal sleeve slot 31. This downwardly holding latch member includes a lower dog 38 expandible outwardly by a helical compression spring 39, the inner end of which bears against the sleeve and the outer end of which bears against the dog. The latch member is pivotally mounted on a pin 40 extending therethrough and suitably secured to the sleeve 23, the upper portion of the latch member having an inwardly directed nose 41 adapted to engage the periphery of the mandrel 19 to be held in an outward position and thereby retain the downwardly holding dog 38 in the inward position, as described in FIG. ld.

The elevation of the mandrel 19 within the sleeve 23 to position a longitudinally extending groove 42 of the mandrel in alignment with the retracting nose 41 will allow the spring 39 to shift the dog 38 outwardlyfor movement into the coupling space 11 and for engagement with the upper end 43 of the lower tubing section 13 for the purpose of preventing downward movement of the sleeve 23 therewithin. The upper end 44 of the groove 42 is tapered, being engageable with the nose 41, when the latter is disposed in the groove, for the purpose of shifting the upper part of the latch outwardly and its lower dog 38 inwardly from the coupling space, as described hereinbelow.

Initially, the latch sleeve 23 is disposed in a position in which the kdownwardly holding dog 38 is in its retracted position, but the upwardly holding dog 30 can be expanded outwardly by its spring 31, as permitted by the location of its retracting nose 33 in the groove 34. The sleeve 23` and mandrel 19 are held in such relative position by an interconnecting yshear screw 45. When the shear screw is disrupted, as described hereinbelow, the mandrel 19 can move upwardly and place the -other groove 42 opposite the retracting nose 41 of the downwardly Iholding latch 36, allowing the dog 38 of the latter to move outwardly into the coupling space 11. Such position is definitely determined by the entry of a radial lock pin 46 disposed in a socket 47 in the mandrel 19 into a groove 48 in the sleeve, the pin being urged in an outward direction by a compression spring 49 in the socket bearing thereagainst, as well as against the base of the socket. The parts are then located in the position illustrated in FIGS. 3d.

Retraction of both latch members 28, 36 from the coupling recess 11, when the apparatus is to be released from the tubing string B, occurs as a result of exerting a downward force on the mandrel 19 sufficient to shear the outer portion 50 of the lock pin from its inner portion, whereupon the mandrel 19 can move downwardly Awithin the sleeve to cause the tapered ends 35, 44 of the grooves 34, 42 to engage the retracting noses 33, 41 and shift both latch dogs 30, 38 inwardly from the coupling recess 11 and substantially completely within `the contines of the latch sleeve 23, the latches being held in this position by the periphery of the mandrel 19 above the grooves. When the parts are in this position, the sheared pin 46 will slide downwardly along `the inner wall of the sleeve 23 and then be urged outwardly into a lower counterbore 51 in the sleeve, in order to preclude upward movement of the mandrel 19 with respect to the sleeve 23. At this time, the parts are in the positions illustrated in FIG. 4b.

In the specic apparatus illustrated in the drawings, the tubing string is to be perforated a predetermined distance above the coupling by driving the pin or button through its wall, this pin or button preferably having a central passage 52 therethrough. The pin may be made of a suitable erosion resisting hard material, such as tungsten carbide. Its inner end is threadedly connected to a radial retainer screw 53 extending from the end portion of a driving head 54 slidable in opposed transverse grooves 55 formed in the upper end of the mandrel within the housing. These grooves are actually an enlarged portion of the mandrel slot 20, having lower guide surfaces 56 on opposite sides of the slot and also upper guide surfaces 57 on opposite sides of the slot, the upper and lower surfaces 58, 59 of the driving head being slidable along the upper and lower sides 57,` 56 of the grooves. The sides 60 of the driving member `54 are slidable along the parallel sides 61 of the grooves 55 on opposite sides of the slot 20. The driving head is also movable radially through the housing opening 21.

The driving head 54 also has a vertical opening 62 which is substantially T-shaped in cross-section. The forward face 63 of the T-shaped opening or slot 62 is inclined in a downward direction to provide a cam follower driving face for shifting the drive member in a forward or tubing perforating direction; whereas, the rear surfaces 64 of the vertical opening 62 on opposite sidesV Of its narrow slot `portion 65 are inclined downwardly in the opposite direction to provide retracting cam follower faces 64 for shifting the drive member 54 in a rearward or retracting direction. Initially, the driving head or cam follower 54 is disposed fully within the mandrel 19 and the housing 18, as illustrated in FIGS. 1c and 5. It can slide transversely along the grooves 55 and through the housing opening 21 t0 drive the tungsten carbide pin or button 10 through the wall of the tubing B, after which the driving head 54 is shifted in a reverse direction to disconnect the retainer screw 53 from the tungsten carbide pin 10, as by stripping the threaded connection therebetween, and to be returned to its initially retracted position completely within the confines of the housing 18.

The shifting of the driving head 54 and the tubing perforating pin 10 outwardly, as well as retraction of the driving head, is effected by longitudinal or downward movement of an elongate cam actuator 66 within the housing 18 and mandrel 19 and along the driving head. This actuator may be made integral with a piston 67 extending upwardly within the cylinder 15. The longitudinal cam actuator 66 includes a tapered lower driving cam portion 68, which is inclined downwardly in one direction, and an upper retracting cam portion 69, which is inclined upwardly from a meeting high point 70 of the cam with the lower drive cam portion. The cam 66 throughout substantially its entire length is T-shaped in cross-section, with the transverse head 71 of the T extending through the head of the slot or opening 62 in the driving head, the width of the head 71 conforming to the width of the mandrel slot 20 so as to be slidably along its opposed walls 72. The leg 73 of the carn T extends through the narrow portion 65 of the driving head slot, and its outer end 74 may be curved to conform to the curvature of the inner wall of the housing 18 to provide a sliding surface therealong and to be supported thereby. The outer surface 75 of the lower drive cam 68 is inclined in a direction conforming to the direction of inclination or taper of the driving face 63 of the driving head 54; whereas, the rear cam faces 76 on the retracting cam portion 69 are inclined in conformance with the extent of taper of the retracting faces 64 on the driving head.

Initially, the cam member 66 is disposed in an upper position within the housing 18, as determined by engagement of its upper shoulder 77 with the lower end of the cylinder sleeve 16, at which time the lower end of the cam 66 is disposed within the drive head 54, as shown in FIGS. lc and 5, the cam follower driving head then bei-ng in its fully retracted position. The parts are initially retained in such position by a shear screw 78 interconnecting the cam 66 and the housing 18.

Upon downward movement of the cam 66, following shearing of the screw 78, the lower cam portion 68 engages the driving face 63 of the head 54 to force the latter and the tungsten carbide pin 10 bearing against its outer surface in a direction outwardly of the mandrel 19 and housing 1S, the pin engaging the inner wall of the tubing B and being forced therethrough to effect its perforation. The maximum outward movement of the driving head 54 and the pin 10 is obtained when the juncture 70 between the driving and retracting cam portions 68, 69 is disposed within the head, such as disclosed in FIG. 3c. A continuation of the downward movement of the cam 66 in the housing 18 and along the mandrel will then cause the retracting faces 76 of the upper cam member 69 to engage the companion retracting faces 64 on the driving head 54, which will cause the head to be shifted inwardly of the housing 18 to a retracted position, The gripping force of the tubing B against the hollow pin 10 is such that inward movement of the head 54 strips the threads of the retaining pin 53 from the button 10, disconnecting these parts from one another, whereupon the head 54 shifts inwardly to its retracted position within the housing, which position will be obtained when the .5 cam 66 is in its lowermost position within the housing 18 and mandrel 19, such as disclosed in FIG. 4m.

The piston 67 is slidably mounted in the cylinder 15, the piston being elongate and having an upper head 80 adapted to slidably seal along the wall of the cyli-nder sleeve 16, as by mounting one or a plurality of piston rings 81 on the head for engagement with the cylinder wall. A suitable bleeder hole 82 can be provided through the lower portion of the cylinder sleeve 16 to facilitate downward movement of the piston within the cylinder 15. Mou-nted in the cylinder above the piston 67 is a propellant or power charge 83 containing its own source of oxygen, which propellant or power charge is adapted to be ignited by a blank cartridge 84 mounted within the upper gun barrel portion 85 of the upper cylinder head 17, which has a passage 86 leading from the cartridge into the cylinder below the head 17 and containing the power charge. The propellant 83 may be provided in stick form, pellet form, or powder form, one specific type of propellant or power charge being described in United States Patent No. 2,640,547.

When the cartridge 84 is fired, the flame issuing therefrom in a downward direction ignites the propellant 83. This blank cartridge is red by a firing pin 87 slidably mounted in a breechblock or cap 88 disposed across the upper end of the gun barrel, being clamped thereagainst by an inwardly directed flange 89 of a housing 9@ secured to the cylinder head 17. Fluid leakage into the gun barrel is prevented by a suitable gasket seal 91 between the breechblock and the upper end of the barrel 85. The firing pi-n has a lower projection 92 extending through the breechblock which is adapted to strike the upper end of the cartridge 84. It also has an upwardly extending stem 93 projecting through the ange 89 into the interior of the housing 98. This stem is adapted to be hit or struck by a striker member 94 mounted within the housing 99 and disposed initially a substantial distance above the tiring pin stem 93. The striker 94 is slidable in the housing and has an upwardly extending arm 95 at one side secured to a mandrel 96 by a shear screw 97. Movement of the striker 94 and mandrel 96 in an upward direction within the housing is limited by engagement of the upper end of the arm 95 with a head 98 extending into the housing 90 and threadedly secured thereto. The mandrel has a stop ange 99 disposed within the housing and adapted to engage the lower end of the head 98, after the shear screw 97 has been disrupted. This stop flange 99 also functions as an upper seat for a helical compression spring 100 disposed within the housing 90 and along the striker arm 95, the lower end of the spring engaging the striker. This spring is retained in appropriate operative position, when in its compressed condition, by an aligning pin 101 integral with and depending from the mandrel 96. The striker also has a plurality of longitudinal bypass ports 102 therein to prevent air or other fluid in the housing 90 from retarding its downward movement when the compression spring 100 is released as a result of shearing of the -pin 97, as described hereinbelow.

The mandrel 96 is movable downwardly within the housing to an extent limited by engagement of the upper end of an upper sub 103 threaded on the upper end of the mandrel with the upper end of the head 98. The upper end of this sub is threadedly attached to sinker bars or a set of jars 104, which are, in turn, suitably secured to the wire line C extending to the top of the well bore.

For the purpose of facilitating compression of the spring 100 and attachment of the striker arm 95 to the mandrel 96, the housing 90 has a suitable lateral access hole 105 therethrough, which is, at first, open to the exterior of the housing. Prior to assembly of the housing 99 to the upper cylinder head 17, the striker 94 is disposed in the housing 90 and the spring 100 also placed therein. The mandrel 96 is then lowered into the housing, the striker resting upon the flange 89, at which time the threaded hole 106 of the striker arm 95 is aligned with the access hole 185. The mandrel 96 is then shifted downwardly to compress the spring until its threaded hole 107 for the shear screw 97 is aligned with the arm hole 106, whereupon the shear screw 97 can be inserted through the access hole and threaded into the arm hole 106 and the mandrel hole 107, which will serve to secure the striker mechanism 94 to the mandrel 96 with the spring 190 in its highly compressed condition. The head 98 can then be slipped over the mandrel 96 and threaded into the housing 90. A cover sleeve 108 is slipped over the housing 90 to cover the opening 185, the housing then being assembled on the upper cylinder head 17, with the firing pin 87, breechblock 88, blank cartridge 84, and propellant 83 in their proper positions. The attachment of the upper sub 103 to the mandrel 96 will prevent the mandrel from moving downwardly suciently for the striker 94 to engage the firing pi-n stem 93.

When it is desired to perforate the tubular string B at a location neighboring a particular coupling 14, the apparatus A is suitably secured to the wire line C with the parts in their relative positions shown in FIGS. la to ld. At this time, the piston 67 and cam mechanism 66 are in their upper positions within the cylinder 15, housing 18 and mandrel 19, the shear screw 78 retaining them in such position. The latch sleeve 23 is secured by the shear screw 45 to the mandrel 19 in the position shown in FIG. la', in which the downwardly holding latch member 36 is in its ineffective or retracted position, the upwardly holding latch member 28, however, being adapted to be shifted outwardly by its spring 31.

The apparatus A is lowered in the tubular string B on the wire line C, the upwardly holding latch 28 freely sliding along the tubing wall and shifting readily into and out of coupling spaces formed by the couplings in the tubing string connecting adjacent tubing sections to one another. The apparatus is lowered to the desired point at which the tubing is to be perforated, and to a distance below such point at which the upwardly holding coupling has moved down a short distance below a coupling space 11 thereabove. The apparatus is then pulled upwardly slowly until the upwardly holding dog 30 shifts into the space 11 and engages the lower end 32 of the upper tubing section 12, thereby preventing further upward movement of the latch sleeve 23 and of the mandrel 19 connected thereto through the agency of the shear screw 45. Shearing of this screw is readily accomplished by jarring upwardly on the wire line C. Following its shearing, the mandrel 19 can be pulled upwardly until the lock pin 46 is disposed opposite the sleeve groove 48, the spring 49 shifting the pin into this groove and locking the mandrel 19 to the sleeve 23. At this time, the mandrel groove 42 is opposite the retracting nose 41 of the downwardly holding latch 36, which allows its spring 39 to shift its dog 38 outwardly into the lock recess 11, thereby securing the lock sleeve 23 and the mandrel 19 to the tubing B against longitudinal movement in both directions, which also prevents longitudinal movement of the housing 18 and cylinder 15 and of the housing 90 surrounding the firing pin mechanism.

Another upward jar is then taken through the wire line C on the mechanism, which will shear the screw 97 securing the mandrel 96 to the actuator arm 95 and allow the tiring spring to propel the actuator 94 downwardly into contact with the tiring pin 87 with sucient force to fire the blank cartridge 84, the ame emanating therefrom igniting the power charge 83 in the propellant chamber above the piston 67. The pressure generated by the burning of the power charge 83 acts downwardly on the piston 67 and also upwardly on the cylinder 15. However, the cylinder is prevented from shifting by being locked to the tubing B through the latch mechanism 23-49 (FIG. 3d). The downward force on the piston 67 shears the screw 78 and then shifts the piston 67 and cam 66 downwardly, the lower cam member 68, because of its inclination, engaging the driving face 63 of the head 54 and forcing the latter and the hollow pin 10 attached thereto outwardly to the extent at which the pin is forced against and through the wall of the tubing string B, the maximum outward projection of the pin through the tubing string being determined when the upper end 70 of the lower driving cam is disposed within the driving head.

The propellant 83 is progressively burning to generate gas at an increasing pressure within the cylinder 15, to continue moving the piston 67 downwardly in the cylinder 15 and also shift the cam 66 downwardly within the housing 18 and the lower mandrel 19. The retracting cam portion 69 then engages the retracting faces 64 of the drive head 54, pulling the drive head inwardly and the retaining screw 53 from the pin 10, the latter remaining in its position through the wall of the tubing B. Downward shifting of the cam 66 continues with the retracting cam surfaces 76 engaging the retracting faces 64 of the drive head 54 to shift the latter inwardly of the housing 18 and of the slotted mandrel 19 to substantially its initial position. When the cam 66 is in its lowermost position within the housing 18, such as disclosed in FIG. 4a, the piston head S0 may uncover the relief port S2 in the 4cylinder 15 to allow the gaseous pressure in the cylinder to bleed through the cylinder sleeve 16 to the exterior of the apparatus and into the tubing string B, the gas pressure thereby being relieved automatically.

The apparatus A can now be released from the tubing string B. The wire line C is manipulated to cause the upper sub 103 to strike a blow against the upper housing head 98 and thereby jar downwardly on the mechanism, such downward jarring action being transmitted from the upper housing 90 through the cylinder 15, lower housing 18, and mandrel 19 to the coupling pin 46. Downward movement of the sleeve 23 is prevented by engagement of the downwardly holding dog 38 against the upper end 43 of the lower tubing section 13. The downward jarring action will shear the portion 50 of the pin within the sleeve groove 4S from its remaining inner portion, disconnecting the mandrel 19 from the sleeve 23 and allowing the mandrel to move downwardly therewithin to a position in which the tapered or inclined upper ends 35, 44 of the mandrel grooves 34, 42 engage the retracting noses 33, 41 on the latches 28, 36 to shift such nose portions of the latches outwardly and their dog portions 30, 38 inwardly against the force of the springs 31, 39. The mandrel 19 will shift downwardly to a position in which the remainder of the pin 46 is disposed below the shoulder 51a of the sleeve counterbore 51, the pin 46 coupling the sleeve 23 to the mandrel 19. The parts are now in the position illustrated in FIG. 4b, the periphery of the mandrel 19 retaining the latches 2S, 36 in their retracted position substantially fully within the confines of the latch sleeve 23. The entire apparatus can now be withdrawn from the tubular string B to the top of the well bore, leaving the perforating member embedded in and extending through the wall of the tubing B, with its central passage 52 therethrough. A perforation or port 52 is thereby established through the tubing string B between its exterior and interior through which fluids can liow.

I claim:

1. In apparatus for perforating a tubular string disposed in a well bore: fluid actuated means adapted to be lowered in the tubular string on a running-in string and having relatively movable first and second members; perforating means carried by and movable laterally of said first member into engagement with the tubular string to perforate the same; means connected to said first member for securing said first member to the tubular string against both upward and downward movement therewithin; actuating means shiftable by said second member and engaging said perforating means to move said perforating means laterally; and means providing a fluid under pressure in said fluid actuated means to exert a force on said second member shifting it relative to said first ymember to shift said actuating means and move said perforating means laterally outwardly into engagement with the tubular string to perforate the same.

2. In apparatus for perforating a tubular string disposed in a well bore: fiuid actuated means adapted to be lowered in the tubular string on a running-in string and having relatively movable first and second members; perforating means carried by and movable laterally of said first member into engagement with the tubular string to perforate the same; means connected to said first member for securing said first member to the tubular string against both upward and downward movement therewithin; actuating means shiftable by said second member and engaging said perforating means to move said perforating means laterally; means providing a fiuid under pressure in said uid actuated means to exert a force on said second member shifting it relative to said first member to shift said actuating means and move said perforating means laterally outwardly into engagement with the tubular string to perforate the same; said actuating means comprising means engageable with said perforating means to retract at least a portion of said perforating means in a direction away from the tubular string; and means for releasing said securing means from the tubular string.

3. In apparatus for perforating a tubular string disposed in a well bore: fiuid actuated means adapted to be lowered in the tubular string on a running-in string and having relatively movable first and second members; perforating means carried by and movable laterally of said first member into engagement with the tubular string to perforate the same; longitudinal cam means engaging said perforating means and shiftable by said second member along said perforating means, said cam means including a first portion tapering longitudinally in one direction to shift said perforating means laterally outwardly and a second portion tapering longitudinally in the opposite direction to shift at least a portion of said perforating means laterally inwardly; means for securing said first member to the tubular string against both upward and downward movement therewithin and means providing a fluid under pressure in said fluid actuated means to exert a force on said scond member shifting it longitudinally of said first member to shift said cam means longitudinally along said perforating means and move said perforating means laterally outwardly into engagement with the tubular string to perforate the same and then move at least said portion of said perforating means laterally inwardly from the tubular string.

4. In apparatus for perforating a tubular string disposed in a Well bore: iiuid actuated means adapted to be lowered in the tubular string on a running-in string and having relatively movable iirst and second members; perforating means carried by and movable laterally of said first member into engagement with the tubular string to perforate the same; means connected to said iirst member for securing said first member to the tubular string against both upward and downward movement therewithin; longitudinal cam means engaging said perforating means and shiftable by said second member along said perforating means, said cam means including a first portion tapering longitudinally in one direction to shift said perforating means laterally outwardly and a second portion tapering longitudinally in the opposite direction to shift at least a portion of said perforating means laterally inwardly; means providing a fluid under pressure in said fluid actuated means to exert a force on said second member shifting it longitudinally of said rst member to shift said cam means longitudinally along said perforating means and move said perforating means laterally outwardly into engagement with the tubular string t0 perforate the same and then move at least said portion of said perforating means laterally inwardly from the tubular string; and means for releasing said securing means from the tubular string.

5. In apparatus for perforating a tubular string disposed in a Well bore, the tubular string having a space therein: fluid actuated means adapted to be lowered in the tubular string on a running-in string and having relatively movable rst and second members; perforating means carried by and movable laterally of said first member into engagement with the tubular string to perforate the same; means connected to said first member and comprising an upwardly holding latch and a downwardly holding latch movable outwardly into the tubular string space to secure said iirst member to the tubular string against longitudinal movement in both directions; actuating means shiftable by said second member and engaging said perforating means to move said perforating means laterally; means providing a uid under pressure in said uid actuated means to exert a force on said second member shifting it relative to said first member to shift said actuating means and move said perforating means laterally outwardly into engagement with the tubular string to perforate the same; said actuating means comprising means engageable with said perforating means to retract at least a portion of said perforating means in a direction away from the tubular string; and means for shifting said latches inwardly from the tubular string space.

6. In apparatus for perforating a tubular string disposed in a well bore: a cylinder; a piston in said cylinder; perforating means carried by said cylinder and including a laterally movable drive member and a perforating element secured thereto; an actuator engaging said drive member and operatively connected to said piston; means for releasably securing said perforating means to the tubular string against both upward and downward movement therewithin; means providing a fluid under pressure in said cylinder to shift said piston downwardly in said cylinder and said actuator downwardly along said drive member to force said drive member and element laterally outwardly to drive the perforating element into the wall of the tubular string.

7. In apparatus for perforating a tubular string disposed in a well bore: a cylinder; a piston in said cylinder; perforating means carried by said cylinder and including a laterally movable drive member and a perforating element secured thereto; an actuator engaging said drive member and operatively connected to said piston; means for releasably securing said perforating means to the tubular string against both upward and downward movement therewithin; means providing a fluid under pressure in said cylinder to shift said piston downwardly in said cylinder and said actuator downwardly along said drive member to force said drive member and element laterally outwardly to drive the perforating element into the wall of the tubular string; said actuator including means engaging said drive member to shift said drive member laterally inwardly upon continued downward movement of said piston means and actuator; and means for releasing said securing means from the tubular string.

8. In apparatus for perforating a tubular string dis- .posed in a well bore: a cylinder; a piston in said cylinder; perforating means carried Aby said cylinder and including a laterally ymovable drive member and a perforating element secured thereto; a longitudinal cam engaging said drive member and operatively connected to said piston, said cam including a lower tapered portion to shift said drive member and perforating element laterally outwardly and an upper tapered porti-on to shift said drive member laterally inwardly; means for releasably securing said perforating means to the tubular string against both upward and downward movement therewithin; and means providing a uid under pressure in said cylinder to shift said piston downwardly in said cylinder and said cam downwardly along said drive -member to iirst force said drive member and element laterally outwardly to drive the perforating element into the wall of the tubular string and to then retract said drive member from the wall of the tubular string.

9. In apparatus adapted to be lowered on a running-in string into a tubular string disposed in a well bore to perforate the tubular string: a cylinder; a piston in said cylinder; perforating means carried by said cylinder and including a laterally movable drive member and a perforating element secured thereto; an actuator engaging said drive member and operatively connected to said piston; means connected to said perforating means for releasably securing said perforating means to the tubular string against both upward and downward movement therewithin; means for generating a gas under pressure in said cylinder to shift said piston downwardly in said cylinder and said actuator downwardly along said drive member to force said drive member and element laterally outwardly to drive the perforating element into the wall of the tubular string; means responsive to manipulation of the running-in string for initiating operation of said gas generating means; said actuator including means engaging said drive member to shift the drive member laterally inwardly upon continued downward movement of said piston rmeans and actuator; and means responsive to manipulation of the running-in string for releasing said securing means from the tubular string to allow said apparatus to be withdrawn as a unit from the tubular string.

10. In apparatus adapted to be lowered on a runningin string into a tubular string disposed in a well bore to perforate the tubular string, the tubular string having a latch receiving space therein: a cylinder; a piston in said cylinder; perforating means carried by said cylinder and including a laterally movable drive member and a perforating element secured thereto; an actuator engaging said drive member and operatively connected to said piston; means connected to said perforating means and comprising an upwardly holding latch and a downwardly holding latch movable outwardly into the tubular string space to secure said perforating means and cylinder to the tubular string against longitudinal movement in both directions; means for generating a gas under pressure in said cylinder to shift said piston downwardly in said cylinder and said actuator downwardly along said drive member to force said drive member and element laterally outwardly to drive the perforating element into the wall of the tubular string; said actuator comprising means engageable with said drive member to retract said drive member from the wall of the tubular string upon continued downward -movement of said piston means and actuator; means responsive to manipulation of the running-in string for initiating operation of said gas generatlng means; and means responsive to manipulation 4of the running-in string for releasing said latch from the tubular strlng Space. 11..In apparatus adapted to be lowered on a running- 1n strmg into a tubular string disposed in a well bore to perforate the tubular string, the tubular string having a latch receiving space therein: a cylinder; a piston in said cylinder; a housing secured to said cylinder; a mandrel in said housing having a guide slot therein; a drive member movable laterally in said slot; a perforating element attached to said drive member; a cam secured to said piston and slidable in said slot, said cam including a lower portion tapering downwardly and engageable with said drive member and an upper portion tapering upwardly and engageable with said drive member; means for generating a gas under pressure in said cylinder to shift said piston downwardly and said cam downwardly along said drive member to force said drive member and element laterally outwardly to force the perforating element into the wall `of the tubular string and to then retract the drive member; means for initiating operation of said gas generating means; a sleeve releasably secured to said mandrel; an upwardly holding latch and a downwardly holding latch on said sleeve shiftable into the space to prevent longitudinal movement of said mandrel, housing and cylinder in both directions in the tubular string;

11 and means on said mandrel engageable with said latch to retract said latch from thefspace.

12. In `apparatus adaptedV to be lowered on a runningfin string into a tubular string disposed in a well bore to perf-orate the tubular string, the tubular string having a latch receiving space therein: a cylinder; a piston in said cylinder; a housing secured to said cylinder; a mandrel in said housing having a guide slot therein; a drive member movable laterally in said slot; a perforating element attached to said drive member; a cam secured to said piston and slidable in said slot, said oam including a lower portion tapering downwardly and engageable with said drive member and an upper portion tapering upwardly and engageable with `said drive member; means for generating a gas under pressure in said cylinder toshift said piston downwardly and said cam downwardly along said drive member to force said drive member and element laterally outwardly to force the perforating element into the wall of the tubular string and `to then retract theV drive member; means for initiating operation of said gas generating means; a sleeve on said mandrel; upwardly and downwardly .holding latches on said sleeve shiftable into the space to prevent movement of said mandrel, housing and cylinder in the tubular string; means releasably securing said sleeve to said mandrel in a rst position whereby said mandrel engages and holds said downwardly holding latch in retracted position, release of said securing means allowing shifting of said mandrel in said sleeve to a second position allowing expansion of said downwardly holding latch into the space; means responsive to manipulation of the running-in string for initiating operation of said gas generating means; said mandrel being shiftable in said sleeve to a third position, whereby said mandrel engages and holds said downwardly holding latch in a released position.

References Cited by the Examiner CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN 'HERSH, Examiner. 

1. IN APPARATUS FOR PERFORATING A TUBULAR STRING DISPOSED IN A WELL BORE: FLUID ACTUATED MEANS ADAPTED TO BE LOWERED IN THE TUBULAR STRING ON A RUNNING-IN STRING AND HAVING RELATIVELY MOVABLE FIRST AND SECOND MEMBERS; PERFORATING MEANS CARRIED BY AND MOVABLE LATERALLY OF SAID FIRST MEMBER INTO ENGAGEMENT WITH THE TUBULAR STRING TO PERFORATE THE SAME; MEANS CONNECTED TO SAID FIRST MEMBER FOR SECURING SAID FIRST MEMBER TO THE TUBULAR STRING AGAINST BOTH UPWARD AND DOWNWARD MOVEMENT THEREWITHIN; ACTUATING MEANS SHIFTABLE BY SAID SECOND MEMBER AND ENGAGING SAID PERFORATING MEANS TO MOVE SAID PERFORATING MEANS LATERALLY; AND MEANS PROVIDING A FLUID UNDER PRESSURE IN SAID FLUID ACTUATED MEANS TO EXERT A FORCE ON SAID SECOND MEMBER SHIFTING IT RELATIVE TO SAID FIRST MEMBER TO SHIFT SAID ACTUATING MEANS AND MOVE SAID PERFORATING MEANS LATERALLY OUTWARDLY INTO ENGAGMENT WITH THE TUBULAR STRING TO PERFORATE THE SAME. 